// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_MEDIA_MIDI_HOST_H_
#define CONTENT_BROWSER_MEDIA_MIDI_HOST_H_

#include <stddef.h>
#include <stdint.h>

#include <memory>
#include <vector>

#include "base/gtest_prod_util.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_vector.h"
#include "base/synchronization/lock.h"
#include "content/common/content_export.h"
#include "content/public/browser/browser_message_filter.h"
#include "content/public/browser/browser_thread.h"
#include "media/midi/midi_manager.h"
#include "media/midi/midi_port_info.h"
#include "media/midi/midi_service.mojom.h"

namespace midi {
class MidiService;
class MidiMessageQueue;
} // namespace midi

namespace content {

class CONTENT_EXPORT MidiHost : public BrowserMessageFilter,
                                public midi::MidiManagerClient {
public:
    // Called from UI thread from the owner of this object.
    MidiHost(int renderer_process_id, midi::MidiService* midi_service);

    // BrowserMessageFilter implementation.
    void OnChannelClosing() override;
    void OnDestruct() const override;
    bool OnMessageReceived(const IPC::Message& message) override;

    // MidiManagerClient implementation.
    void CompleteStartSession(midi::mojom::Result result) override;
    void AddInputPort(const midi::MidiPortInfo& info) override;
    void AddOutputPort(const midi::MidiPortInfo& info) override;
    void SetInputPortState(uint32_t port, midi::mojom::PortState state) override;
    void SetOutputPortState(uint32_t port, midi::mojom::PortState state) override;
    void ReceiveMidiData(uint32_t port,
        const uint8_t* data,
        size_t length,
        double timestamp) override;
    void AccumulateMidiBytesSent(size_t n) override;
    void Detach() override;

    // Start session to access MIDI hardware.
    void OnStartSession();

    // Data to be sent to a MIDI output port.
    void OnSendData(uint32_t port,
        const std::vector<uint8_t>& data,
        double timestamp);

    void OnEndSession();

protected:
    ~MidiHost() override;

private:
    friend class base::DeleteHelper<MidiHost>;
    friend class BrowserThread;

    int renderer_process_id_;

    // Represents if the renderer has a permission to send/receive MIDI SysEX
    // messages.
    bool has_sys_ex_permission_;

    // Represents if a session is requested to start.
    bool is_session_requested_;

    // |midi_service_| manages a MidiManager instance that talks to
    // platform-specific MIDI APIs.  It can be nullptr after detached.
    midi::MidiService* midi_service_;

    // Buffers where data sent from each MIDI input port is stored.
    ScopedVector<midi::MidiMessageQueue> received_messages_queues_;

    // Protects access to |received_messages_queues_|;
    base::Lock messages_queues_lock_;

    // The number of bytes sent to the platform-specific MIDI sending
    // system, but not yet completed.
    size_t sent_bytes_in_flight_;

    // The number of bytes successfully sent since the last time
    // we've acknowledged back to the renderer.
    size_t bytes_sent_since_last_acknowledgement_;

    // Protects access to |sent_bytes_in_flight_|.
    base::Lock in_flight_lock_;

    // How many output port exists.
    uint32_t output_port_count_;

    // Protects access to |output_port_count_|.
    base::Lock output_port_count_lock_;

    DISALLOW_COPY_AND_ASSIGN(MidiHost);
};

} // namespace content

#endif // CONTENT_BROWSER_MEDIA_MIDI_HOST_H_
